package cl.antartis.interac.ejb;

import java.math.BigInteger;
import java.util.Date;
import java.util.Random;
import java.util.zip.CRC32;

public class Keygen
{
   /**
    * @param s
    * @param i
    * @param bytes
    * @return
    */
   public static short getCRC(String s, int i, byte bytes[])
   {
       CRC32 crc32 = new CRC32();
       if (s != null)
       {
           for (int j = 0; j < s.length(); j++)
           {
               char c = s.charAt(j);
               crc32.update(c);
           }
       }
       crc32.update(i);
       crc32.update(i >> 8);
       crc32.update(i >> 16);
       crc32.update(i >> 24);
       for (int k = 0; k < bytes.length - 2; k++)
       {
           byte byte0 = bytes[k];
           crc32.update(byte0);
       }
       return (short) (int) crc32.getValue();
   }
   /**
    * @param biginteger
    * @return String
    */
   public static String encodeGroups(BigInteger biginteger)
   {
       BigInteger beginner1 = BigInteger.valueOf(0x39aa400L);
       StringBuilder sb = new StringBuilder();
       for (int i = 0; biginteger.compareTo(BigInteger.ZERO) != 0; i++)
       {
           int j = biginteger.mod(beginner1).intValue();
           String s1 = encodeGroup(j);
           if (i > 0)
           {
               sb.append("-");
           }
           sb.append(s1);
           biginteger = biginteger.divide(beginner1);
       }
       return sb.toString();
   }
   /**
    * @param i
    * @return
    */
   public static String encodeGroup(int i)
   {
       StringBuilder sb = new StringBuilder();
       for (int j = 0; j < 5; j++)
       {
           int k = i % 36;
           char c;
           if (k < 10)
           {
               c = (char) (48 + k);
           }
           else
           {
               c = (char) ((65 + k) - 10);
           }
           sb.append(c);
           i /= 36;
       }
       return sb.toString();
   }
   /**
    * @param name
    * @param days
    * @param id
    * @param prtype
    * @return
    */
   public static String MakeKey(String name, int days, int id)
   {
       id %= 100000;
       byte bkey[] = new byte[12];
       bkey[0] = (byte) 1; // Product type: IntelliJ IDEA is 1
       bkey[1] = 14; // Adds support for intelliJ 14
       Date d = new Date();
       long ld = (d.getTime() >> 16);
       bkey[2] = (byte) (ld & 255);
       bkey[3] = (byte) ((ld >> 8) & 255);
       bkey[4] = (byte) ((ld >> 16) & 255);
       bkey[5] = (byte) ((ld >> 24) & 255);
       days &= 0xffff;
       bkey[6] = (byte) (days & 255);
       bkey[7] = (byte) ((days >> 8) & 255);
       bkey[8] = 105;
       bkey[9] = -59;
       bkey[10] = 0;
       bkey[11] = 0;
       int w = getCRC(name, id % 100000, bkey);
       bkey[10] = (byte) (w & 255);
       bkey[11] = (byte) ((w >> 8) & 255);
       BigInteger pow = new BigInteger("89126272330128007543578052027888001981", 10);
       BigInteger mod = new BigInteger("86f71688cdd2612ca117d1f54bdae029", 16);
       BigInteger k0 = new BigInteger(bkey);
       BigInteger k1 = k0.modPow(pow, mod);
       String s0 = Integer.toString(id);
       String sz = "0";
       while (s0.length() != 5)
       {
           s0 = sz.concat(s0);
       }
       s0 = s0.concat("-");
       String s1 = encodeGroups(k1);
       s0 = s0.concat(s1);
       return s0;
   }
   public static void main(String[] args)
   {
       if (args.length == 0)
       {
           System.err.printf("*** Usage: %s name%n", Keygen.class.getCanonicalName());
           System.exit(1);
       }
       Random r = new Random();
       System.out.println(MakeKey(args[0], 0, r.nextInt(100000)));
   }
}
